Internet Giants to Block Child Porn Images

“All children have the right to justice”, “enough”, or “acknowledge CSA” – these were some of the words of protests as Pakistani rights activities staged a protest against CSA (Child Sex Abuse) on 10-Aug-15. A few days back, the Indian Government banned 857 adult sites, and after a public outcry against the rights for freedom of expression granted by the Indian Constitution, the Indian Government was forced to revert the same, but applying the ban to only those sites promoting child pornography.

Banning Child pornography has been a much-awaited trend and companies like Google had promised to remove any such content from their Search results. In fact, Google also routinely checks its mails for any child porn image and on record has got an user, John Henry Skillem arrested for sending indecent images of children to a friend by tipping off police.

Earlier in 2012, the British Prime Minister, David Cameron had asked Google and other search engines to commit themselves technologically to getting the internet rid of child pornography and abuse, and Google had pledged an amount of $1.6 million to a British Charity, Internet Watch Foundation that monitors online child porn. Till then, Google had been already contributing annually 20,000 pounds along with media giants BT, Vodafone, Sky, Telefonica and EE to this organization.

The investments seem to be paying off. The battle against Child pornography is going to be fought with new technology, and with the support of some of the giants in Silicon Valley. Companies like Facebook, Google, Microsoft, Twitter and Yahoo are already working with Internet Watch Foundation (IWF), the UK based charitable foundation to introduce a new system which would detect such content and block online images of child pornography.

This novel technology introduced by Internet Watch Foundation helps in tagging images of sexual abuse with unique hashes. Hashes are codes that are generated by a complex algorithm and act like a digital fingerprint. Each image is uniquely applied with a distinct hash. So, it becomes easy to identify an image from the list of hashes. The IWF would keep a record of all the hashes and share the same list with the five companies working with it.

Once the system is introduced to the participating sites like Google, Facebook, Microsoft, Yahoo or Twitter or any other participating website, any image uploaded to these sites would be scanned and if any image is found which had earlier been tagged, the system would identify its hash, and prevent automatically the same from getting uploaded. In case the participating site is unable to remove content by itself, the member would notify IWF for removal of content, which IWF would do.

The IWF hash list is created primarily by three ways:

The Uniform Resource Locator (URL) is reported by Public and IWF members.

IWF Analyst actively looks for illegal URLs

Content is received from a different source

There are primarily two types of hashes:

PhotoDNA hashes : These hashes are developed by Microsoft and are preferred by the industry in general. This algorithm can identify images even if they are altered.

MD5 & SHA-1 hashes: These hashes are also called cryptographic hashes and they are used to identify identical images.

The Internet Watch Foundation estimates that it can currently eliminate five hundred web pages per day which contain child pornography and as more and more images are identified, the count is expected only to increase. Susie Hargreaves, chief executive of the IWF stated that this new system “could be a game-changer and really steps up the fight against child sexual abuse images online.”

However, as they say, every technology has its limitations. This technology is limited in its coverage. It is unable to cover the areas of the Internet where child pornography is rampant, for example, images which are shared over the darknet (Internet’s illicit underground economy), like peer-to-peer network or Tor are not covered. The Tor network, or the “onion router” network as it is known is architected in such a way that it anonymizes traffic. Users here relay or reroute the requests through a layered structure of a network of computers multiple times, with suitable encryption of such data, thereby making detection of the sender or receiver almost impossible. Moreover, the growth rate of darknet is very high with new stores opening every day, and this is an area which needs to be cracked down to limit considerably child porn, the technology for the same is yet to be developed. However, there have been a few unauthorized attacks on the darknet, and in one such attack on Freedom Hosting site which is the largest and best known service provider, hosting a number of prominent darknet destinations, almost half of its hidden services have been compromised.

Therefore, as the hash list grows for the IWF application, there is a great potential for identifying and blocking millions of images in the internet. However, this technology in itself is not enough and a new technology is to be evolved to block child porn in Tor network and other sites within the darknet as well.

Till that is done, the overall impact of blocking of child porn may not be enough.